Stepwise zinc deposition for high-capacity and long-life anode in aqueous zinc-ion batteries

Abstract

Rechargeable aqueous zinc-ion batteries (AZIBs) are widely studied for energy storage because of their high safety, low cost and high energy/power density. However, the practical application of AZIBs is limited by dendrite formation at the zinc anode under high-depth deposition, which results in reduced cycle life and overall performance. Herein, we propose an effective and scalable stepwise deposition approach that integrates uniform nucleation and dense growth through the construction of ultrathin ZnO nanofiber arrays (ZONAs) on the zinc anode surface, along with the introduction of an anionic surfactant (AS) into the electrolyte. This approach yields a uniform, dense and dendrite-free Zn anode during cycling, maintaining stable cycling for 2100 h under a high deposition depth of 10 mAh cm⁻² at an extremely high current density of 10 mA cm⁻². Additionally, full cells using MnO₂ cathodes exhibit stable cycling for 6000 cycles at 5 A g⁻¹, with a capacity retention of 75%. Furthermore, the pouch-type cell with an area of 90 cm² delivers a capacity of 60 mAh and maintains stable cycling for 540 cycles at 200 mA, highlighting its strong potential for scalability.